With 3DS XL hitting Europe and Japan on 28th July, there'll be a number of 3DS owners that decide to take the plunge. With that in mind you'll need to make sure that you transfer your system account and data, otherwise a lot of saves and costly downloads will disappear — and no-one wants that.

Before we give you the lengthy Nintendo details, here are the key steps:

Before initiating a transfer from your old 3DS to the XL, copy the entire contents of your SD card onto a computer, as backup.

On each system click into your System Settings, tap Other Settings, navigate to page three and select System Transfer. This needs an internet connection for both systems; full details and a video from Nintendo are below.

As the video at the end of this article explains, you should be prompted to put your original SD card in the XL after the transfer, with more instructions to then follow. If you then want to upgrade from a 2GB card to 4GB after the process, copy the 2GB contents to your computer and transfer them to the 4GB card.

Some retailers, such as GAME in the UK, are allowing buyers to take the XL home to transfer, receiving the trade-in offer rates if the 3DS is taken in within 24 hours of the purchase. If trading in check with your retailer of choice, and ensure that any in-store system updates are completed properly.

There you have it, and below is the official Nintendo information that was provided when the system transfer update first arrived.

Once a transfer has been performed, it cannot be undone.

When performing a transfer, the data on the target system will be overwritten with that of the source system. When the transfer completes, the System Memory of the source system will be formatted, deleting all data.

Note: Your System Settings configuration and any stored credit card information will not be transferred. These will be deleted.

When overwriting data on the target system:

Time-limited add-on content and add-on content with a limited number of uses purchased on the target system will be lost.

Any software/add-on content present on the target system will be replaced with that of the source system, and the original target system data will no longer be usable.

Note: Any software and add-on content originally purchased/downloaded on the source system will be usable with the target system.

SD Cards containing data created on the source system will be immediately usable with the target system after the transfer. Data created by the target system on SD Cards will no longer be usable.

Note: Nintendo 3DS Sound recordings and Nintendo 3DS Camera videos and photos will not be deleted and can continue to be used. Nintendo 3DS download software purchased on or downloaded to the target system before performing the transfer can be redownloaded to that system from the Nintendo eShop after the transfer.

The Nintendo eShop balance of the source system will be combined with that of the target system.

Note: The transfer will not be able to be performed if the combined balance would exceed the maximum balance allowed in Nintendo eShop.

There is a limit on the number of times that transfers can be performed. A system cannot participate in a transfer once this number is reached. The number of transfers remaining is displayed whenever you start performing a transfer.

Note: A transfer can only be performed once in a 7-day interval.

Any pre-installed Nintendo 3DS download software will be transferred from the source system to the target system. However if you delete your Nintendo eShop account activity on the target system after the transfer, you will no longer be able to redownload this software to that system from Nintendo eShop.

You may only use the System Transfer feature with systems you own.

You must connect to the internet in order to perform a transfer. The Nintendo 3DS Service User Agreement and Privacy Policy apply when performing a transfer.

The region settings of both systems must match in order to perform a transfer.

Data may be lost if the system runs out of power or is turned off, or if wireless communication is disabled, during the transfer. Check the battery status and signal strength icons before starting the transfer.

If you want a nice colourful chart detailing what's automatically transferred then click on the gallery image below, and the following Nintendo video provides a useful summary. If you want the full low-down on the system itself, meanwhile, check out our 3DS XL hardware review.